December 13, 2014

Voltage regulator for the headlights

I finally got the voltage regulators for my headlight build. It took them (banggood) over a month this time. Banggood shipping hasn't been the best lately (the free shipping that is).

Anyway. The device is one of those really cheap and simple voltage regulators that you can get on ebay, banggood, dx or whatever. They're cheap, light and noisy. If you can live with that, they're fantastic.

I put it to use right away. Please see my updated blog post on the FPV headlight build.

November 25, 2014

Mini-quad headlights for FPV

Now that winter is coming (pun intended) we only have a few hours of sunlight during the day. This means that flying during weekdays are impossible. Even during weekends the time frame is limited.

What if you could put headlights configured correctly to be able to fly FPV during dark hours?

There are a lot of things to think about to get this right and I have no idea where to start.

  • Reflector angle, how to find one that is suitable for the camera I use
  • Light wavelength, what is best for the camera
  • Luminous flux, higher often means heavier gear and more expensive drivers
Since I have no idea where to start I'm going to build a first one just to see what happens. I started out with a headlight LED kit from HobbyKing. It's a bit short on specs but since I wanted to re-solder the wires I had to take it apart and found out a few interesting things.

Voltage step down diodes
PWM switch with voltage step down diodes for headlight system

The setup is specified to run at 6.5-8.4 V. Essentially it is made for 2S since it comes with a 2S connector. To achieve the voltage range they have placed the two LEDs in series and added two diodes to "step down" the voltage by about 1.4V. This is the very cheapest and ineffective way of doing this. As a result each LED run at 2.5-3.5 V. The setup is said to consume 500mA. This would give a per-LED power of about 1.2-1.5W. It's hard to guess but we can maybe expect 100lm to come out of each diode. But thats when the battery is fully charged and unloaded, it will probably be much less when we get close to 6.5V.


When re-soldering the LED wires I tugged one of them a bit hard and decided to the the reflector apart to check internal wiring. It's essentially a plastic reflector assembly with a LED emitter glued to it with a simple heat sink glued to the module. The emitter is a very typical 20mm star device like this one and can be found in a multitude of configurations, prices and qualities from Chinese vendors. If the emitter is not powerful enough it can easily be replaced by a more powerful one.

I have no intentions of using 2S to power the LED. In fact, I have no machines with 2S power systems. Instead I'll be using a cheap voltage regulator to provide the required voltage to the device. I will remove the two diodes and power the headlights using the switch. The switch itself is a quite useful device, it can be bought at hobbyking at almost the same price as the headlight kit. Anyone know where I can get one cheaper?

I'm building the headlight setup like a "module" that I can mount wherever I usually put the mobius. The mobius is useless in low light conditions and obviously will be of no use when I use the head lights. I'm using a glass fiber piece from the rotorbits series, very useful for prototyping.


Headlight LEDs mounted on a piece from the rotorbits

I will use a very cheap voltage regulator to drive the LED. Besides from cheap it is also very light and not current regulating. This is not recommended but I will give it a try to see how bad it can get. The regulator has a dial for setting the output voltage. I adjusted it to 6V to start with and will probably increase it to about 6.6V which is likely to be a suitable voltage for the LEDs.


Voltage regulator and electronic PWM switch
 Those cheap regulators are known to cause some noise which can effect the FPV equipment. This is often due to undersized capacitors. I added additional ceramic capacitors to both the input and output (output should be useless actually) to counter this right away.


Additional capacitors on the voltage regulator.

Once everything was put together I attached the to the plate with the LEDs. I tested the setup on the bench with ESC/Battery/receiver I could live without in case the non-current-regulatory property of the driver would cause imminent death of anything. But nothing happend, the LEDs worked and I increased the voltage a little bit as expected.

I attached a JST connector to source 3S from the power distribution and used the ReceiverPort in PPM+Outputs mode on the CC3D to connect channel 7 to the PWM switch. It took some fiddling with the transmitter and even more with the CC3D to get it working properly. But I now have the headlights on a switch on the transmitter.


Headlights mounted on the 250 mini-quad


Headlights in action (impossible to take a good photo of this)

I ran out of time but got to try them out flying line of sight. I recorded the results of course with a DVR to get the actual FPV view. It turns out the camera handles the low light conditions better than I expected and the headlights does a great job at lighting up branches that you wouldn't see otherwise.






November 9, 2014

Flight controller mounts

Flight controllers are getting smaller and smaller. OpenPilot launched the CC3D Atom a while back which takes another step for the compact builder. But, despite the development, some frames are still made with the old 50x50mm size in mind. They might not even have the common diagonal slots to make mounting a bit more general. Yes, I'm talking about my favorite, the Diatone FPV250.

Both HobbyKing and Banggood (other vendors too) have a few mounts and adapters for the 36mm boards. I ordered a few just to get a feel of how good they are and how well they can be used.


FC Mounts
Flight controller board mounts, top left, top right, bottom left, bottom right.

As seen in the picture you can pick and choose between pure mounts, adapters and adapters with dampers.

Starting from the top left; this is a simple build with two carbon/glass fiber plates, a few holes in them and damper rubbers to hold them together. It's actually an adapter with a wider base. I really like this one, it's compact and has the right "feel" to the dampers. Also, it comes with an seemingly random set of nylon standoffs and screws. The screws are too long and does not fit in the standoffs. I might try this out on the next mini-quad build, maybe in the configuration below.

CC3D mounted on power distribution board and FC mount

To the top right is a 3D-printed adapter-damper mount. It has the right feel to it but looks kind of crappy being 3D-printed. It also has an enormous base and mounting it requires a lot of space. It does not fit inside the pit of the FPV250.

FC mount "on" the FPV250

The two bottom mounts are from HobbyKing. One adapter and one mount. The adapter is really simple and could be used in the FPV250 for a small flight controller. Thanks to the big hole in the middle it leaves a lot of room for the cables.

The last one to the right is the simplest of mounts. I don't really know what this is for since a set of standoffs would probably do the same job. One could imagine using this on the top of the flight controller as a protection. I'm unsure if even an angled set of servo headers would fit. Personally I always solder the signal wires and it would probably work for me.




November 4, 2014

Tri-copter fixes

I finally got around to do some of the adjustments I've been planning for such a long time on the tri-copter. I've had numerous issues with this machine like vibrations, video jello, video interference, bad flight characteristics. Those issues was dealt with today. First off, an image before the remake.


The cable mess

I made three major adjustments today (and a handful small ones):

  • Replace the KK board with a CC3D
  • Improved wiring and mounting of the Mobius
  • Replaced a motor shaft

First off the most invasive one, the controller board. I never had any success with the KK board. I know many come a long way with the board and love it because of its price and the LCD display. But not me, and the CC3D has never let me down before. Everything started with ripping out a lot of connectors and removing the KK.

While replacing the flight controller I also installed a power distribution board for the 5V system. I need to source the LEDs, receiver, flight controller and mobius from the 5V BEC and I want to avoid using the flight controller connectors for power distribution.



LV power distribution
Mini power distribution for 5V
I cut all the ESC and servo wires and soldered them directly. Since I sources ground and 5V from the power distribution to the receiver I only needed one wire for the S-BUS to the flight controller. I made a "special cable" for that.


CC3D mounted
Single wire CC3D connection

I made a new "pad" for the mobius to sit on. Place in a better connection with respect to the video cable, I had a lot of trouble keeping it in place before. I used some left over semi rigid foam and stacked a few pieces to build up the platform.



Mobius mounted
Mobius foamy platform


Then I took a look at the bad motor. I had noticed before that there was probably an issue with the motor, mount or prop. Forums had told me that the prop mounts for the NTM Prop drive motors can be of lesser quality. And it was true. Once I spun it up without the propeller on you could clearly see that the shaft/mount was crocked. I replaced it with a new mount (I ordered three extra just in case) and the issue was resolved.

I tested spinning it up and giving it a short flight indoors and everything worked as it should. The CC3D is still on "factory" defaults but it flew anyway, I did not dare take it out of the ground effect as the space was kind of tight.

I had issues with interference in the FPV gear before and I made an LC filter to counter that. It helped somewhat but apparently not completely. I'm unsure if my filter is insufficient or if I need to add another one to the 5V powering the mobius to prevent the mobius from bridging the interference to the transmitter. I caught the interference issue on video, skip to about 50 seconds to see the liftoff and the black lines it comes with.





November 3, 2014

Crappy chinese CC3D clone from banggood

Since I had gotten two CC3Ds from banggood that where really good, as good as the original ones, I had a third one come in a few weeks back. Today was the day that it was supposed to come into use. It didn't.

Turns out a got a bad one. I already started having suspicions when I took it out of the bag. The PCB on this one was much thinner than my previous ones. And with no greater surprise it turns out that it doesn't have a boot loader on it. Just as many have reported before on various forums.

What to do now? If you consult the forums most will tell you to chuck it and order the good stuff from drotek or similar. But can it be that hard to flash your own bootloader? I'll soon find out. Googling for a few seconds pointed me to a detailed description of the process. I only need to get a FTDI, but they aren't that many euros. I have already ordered one from Hong Kong. Hopefully I'll get it within a few weeks we'll see how well the flashing goes.

Update
It seems not to have been as bad as I suspected. Since I considered the board to need some work to get it working if it would ever I started fiddling with it follow the guide on the openpilot wiki. Turns out I could actually flash a new bootloader onto the device using the rescue method. This means there is actually a bootloader on it but the device failed to boot for some reason, maybe the firmware was missing or corrupted.

Anyway. It seems to be working now. But since the "feel" of the device is not fantastic, I must build another small and cheap machine to put it in. :)

October 22, 2014

Hamradio license and the next build project

I haven't done much building nor flying the last few weeks. I've been spending most of my time studying for a ham radio license to learn about radio systems and the issue we FPV fliers might cause while using out video transmitters.

I've also been waiting for parts. More specifically a CC3D from banggood which took 25 days to get through the Chinese mail system this time. Delivery times from said online vendor are often more than 20 days thus this is not in any way exceptional. The CC3D is part of the rebuild of my tri-copter that I have been planning for some time. The machine has a few issues I need to address.

Vibrations have been an issue from the start. Not a big issue but bad enough to cause jello in my flight footage. I've managed to track down the issue to one of the motors or most likely the prop mount. I'm using NTM Propdrive 2826  motors and there are a few reports of the prop mounts for said motors are quite crappy, but the motors are usually of decent quality. I've ordered a few extra mounts and will try to replace the suspected culprits.

Flight stability has not been what I require from this machine. This is not a racer and I intended to use it for relaxing FPV flying. The KK board has not delivered what I ask for. It is not stable, it does not correct very fast in Attitude mode, it does drift and sometimes gives you small surprises. And it does not speak S-BUS! I will try to use my new favorite, the CC3D, instead which takes time to trim but does not give you any surprises.

Cables are everywhere. Being my first multi rotor build I underestimated the need for planning in terms of where all the cables should go. Now it looks like a mess. I will redo all the signal cabling and thanks to the S-BUS capability of the CC3D I can loose the S-BUS decoder. All the FPV cabling needs to be redone as well.

Camera mounts are not in place. I will fly the machine with a mobius, I've tried it already and it works fine. But right now there's just a cushion with Velcro on it and I could do better than than. I also intend to try to put a GoPro clone on it to see if it beats the Mobius.


X900 with KK2.1.5 and cabling. And a CC3D next to it.

October 2, 2014

Finished the cheapest mini-quad...

...and took it for a test flight today. No FPV flying, I had the camera shutter set up all wrong. But I got to try out the CC3D settings and see if all worked as it should.

Here's the result. I'm very satisfied so far.


September 27, 2014

Broken and fixed single-wire receiver with the CC3D

I messed up today. Big time. I was preparing to wire a Fasst S-BUS receiver to a CC3D. I do this by removing the servo connector and soldering the wires directly to get a more compact build. I'm using the Corona R4FA-SB which can either operate in 4-channel PWM mode or a "special" mode with S-BUS. PPM and RSSI-PWM outputs. I intended to use it in special mode with the S-BUS wired to the CC3D.

However, I manged to break it while removing the servo connector pins. The only important soldering pad, the S-BUS one, was broken away from the receiver. This is catastrophic, it might mean that the receiver is ready for the garbage bin.

Lost soldering pad
I managed to track down a new location to possibly solder then S-BUS signal cable. A small area between two tiny surface mounted resistors (I think). So I tried it out.


I soldered the signal cable and the power cables. Wrapped it in heat shrink and added a small bead of hot glue to avoid any possible stress on the tiny signal cable. But when I hooked it up to the CC3D there was nothing.



But I decided to go to Google and quickly realized that you can use the PPM as input to the CC3D as well. It's connected to a different input port on the CC3D and it comes with less precision and higher latency than S-BUS but it'll have to do for this build. Some cutting and soldering and configuring of the CC3D and it worked! Turns out you need to use output channel 2 which carries positive PPM.


CC3D installation with receiver, hidden below


September 25, 2014

Scrap mini-quad build: power system finished

Yesterday and today I managed to get started with the new mini-quad build. I started by de-soldering the connectors on the CC3D as I will solder all or most cables on this build.

I've also soldered the motors and test-run them to make sure the work and spin in the right direction. Looking "good" so far. There are notable differences between the motors.

Motors soldered to the ESCs

Motors and ESCs attached and soldered to the frame

I've also started the build page for better documentation.

September 23, 2014

Scrap mini-quad build, inventory check

I got my last items for the scrap/cheapest mini FPV quad build the other day and it's time for the inventory check.

Parts for the mini-quad build

I few things are not on the picture, I've left out wires, heat shrink and parts for the FPV filter. Right now I'm only short on propellers. I know I have them somewhere. And the FPV OSD. I know I've seen that around somewhere as well.


September 22, 2014

Chinese CC3D

After a long wait I got a chinese CC3D today. I've been warned about these things but I was just too curious to not try it. I already have two original CC3D and they fly great but are a tad bit too expensive for my next scrap build. So I wanted to give this one a try. I bought the CC3D from banggood and got myself a 3D-printed protective case while I was at it.

First impression is positive. Most reports about the CC3Ds have been that they come without bootloader, which makes them more or less unusable by most people. But this particular one came with the latest firmware, which is positive. Hooking it up to the GCS just worked and everything seems to react as it should. I HAVE NOT flown it yet and there are still a great chance/risk that the sensors are not of top quality!

CC3D with 3D-printed hard case

This device has something that is different from the two I already have. It has the SWD connector soldered on the board. I will hopefully never ever use this connector and it does not really matter except for one thing. It does not fit into the hard case that I ordered with it. But it's not impossible to fix.

September 19, 2014

I learned what New Caledonia is today!

I've been waiting almost a month for one of my orders from banggood and the tracking hasn't been updated for 3 weeks. The last tracking information was flight departure from China.

I mailed banggood about this and they just responded that it might be because of the bad weather. But that I should wait a bit longer. And now it turns out that it might actually be because of some bad weather because the airplane apparently dropped my package over the Atlantic where it has been swimming around for a while.

Today, I got the big surprise. The tracking information has been updated and the package was apparently sent from "New Caledonia". Wow. This is like when HobbyKing sent their packages via Fiji. I had too google New Caledonia. Now I know where it is and why it is taking some time...

September 11, 2014

Ridiculous battery connector

I used to fly my 250 helicopters with the same 1300mah 3S batteries I use for the mini-quads. This simply to avoid having many different battery configurations. Those batteries are actually slightly too large for that application. I also used the EC3 connector on said helicopters. Which is not easy. They are hard to fit under the canopy and hard to disconnect without ruining the little helicopter.


EC3 connector on a CopterX 250


The 250 helicopters usually comes with a JST on them and today I finally gave up and started the move to smaller batteries and smaller connectors. I will use a 1000mAh configuration instead. 850mAh is actually the recommended size but most 850mAh batteries have high C-rating and are as heavy as a 1000mAh 20C. And 20C is 5A more than the 15A ESC can handle.


JST connector


I got two batteries in the mail today and they had said JST connector already. Which is great. So I started by changing connector on the CopterX 250. That was easy.

But then it came down to an "old" Turnigy battery of the same configuration I had laying around. This one was equipped with a XT60 connector and a 14awg wire. This is a battery built to deliver over 60A and I'm gonna pull 10 maybe 12 out of it. Alright, so how do you put a JST connector on a 12awg wire?


I did it by uncovering the cable and cutting away half of the strands inside.




After that I used heat shrink tube in two steps to get down to a size that can pass into the JST connector.

Heatshrink step down metod to reduce the cable size

JST connector crimped onto the cable



And then, when it all comes together, it looks really awesome. Or ridiculous. (sorry for the quality)


JST on 14awg wire!





September 7, 2014

Fixes for the CopterX 450

I got a few spare parts today to fix the CopterX 450 after this summers aluminium failure and following emergency landing. I replaced the broken tail servo mount with a plastic stock Align one. Also, the landing gears broke when I took it down and I had a spare Align ones in the drawer. You can see the new servo mount and the new white landing skids in the picture.

Tail servo mount
Tail servo mount

While I was at it I installed a metal canopy holder. I have always dreamed of these when the ordinary servo rubber pops out or breaks.

Canopy holders
Canopy holders

You have to cut out a larger hole in the canopy and there is no going back. Pay close attention not to damage the threads when screwing them together. I tightened them unmounted first to press the outer o-ring together a little bit. This made it easier to make the threads grip while mounting them on the canopy.

Once in place, the work really well. Attaching and removing the canopy is much easier than before and it is still held firmly in place while mounted.



20140907_211510

September 3, 2014

Diatone 17# finished

I've had it sitting all put together without flying it for a couple of weeks now. The lack of spare time during daylight has kept me from adjusting the flight controller. But yesterday I got two spare hours and got it done.

I used the TxPID module on the CC3D this time and it went much smother than the previous one. I think I got a decent setup this time.

I've only setup the attitude mode so far. Hopefully I get a few hours this weekend to fly it FPV, setup the rate mode and possibly adjust the camera.

Check out the build page for all the gory details!

September 2, 2014

Diatone 18# from HobbyKing, but not the latest version

Malaysia post lost two of my packages from HobbyKing about 3 months ago. And that's the time it takes for HobbyKing to process the complaint and everything before you can get your refund.

Anyway. With some dollars on the point account I went shopping for some lipos that I've considering for testing a lighter configuration on my EDF and the 250 helis. While doing this I discovered that HobbyKing has a new mini quad frame that they call the Slick 220. It is a Diatone 18# but version 1. Version 1? Seriously, banggood has been selling version 3 for some time now!

The 18# frames are nice and I liked the build quality of my 17#. But they're a bit heavy. If they could (and they should be able to) shave off some 50g from their frame they'd be even better.

August 21, 2014

Next project, a cheapest mini quad?

The bench has a lot of things waiting. A 450 in need of landing skids and tail servo mount. A 550 in need of service and upgrades. A 250 in need of a proper gyro setup (3GX). A tri-copter in need of improved electronics and a fixed prop mount.

But right now I know other things that are more interesting. FPV quad copters of the smaller kinds! Having finished my second I realized both my mini-quads suffer from a particular drawback, the price. I did the math on my last build and ended up with a whooping $470. It sounds a lot but when you break it down and look at the choice of flight controller, the choice of telemetry radio and sensors, the choice of brand name video transmitter it is actually not that exceptional.

The biggest problem with this is that I fear of flying at certain locations knowing that a crash would be expensive. Areas such as over water or over dense underbrush. Battling this problem is easy, by building a cheaper machine, picking parts only (or almost only) based on price and what I already have in the drawers. I took half an hour today to put a build together.


  • Frame: Diatone FPV250 v2. I have gotten this one already to get the landing gear I lost earlier.
  • ESC: RCX SimonK 10A.
  • Flight controller: CC3D Clone. Yes, it hurts, but it's a better option than the equally priced KK.
  • Motors: RCX 1804 2400Kv. There are options at the same price, but I already have two of those.
  • Receiver: Corona R4FA-SB. There are cheaper 6ch non-sbus FASST receivers, but I already got one of those in the drawer.
  • OSD: Super Simple OSD. I'm going with OSD instead of telemetry. This is the cheapest one.
  • VTx: SkyZone TS 5823 200mW. There are cheaper ones but they usually don't work with Fatshark. This one I got already
  • Camera: Sony Super HAD-II mini

This configuration sums up to about $200. You can probably shave off a few dollars on the receiver, video transmitter and choosing a not so good camera, but this is as far as my compromises go.

August 18, 2014

Power distribution boards

I've never used power distribution boards for my builds but I did consider it for my last build but decided not to use one. I think that might have been a mistake, the build would have been easier with a power distribution board. Even though I don't use them yet, I ordered a few (since they aren't very costly) to get a good look at what they offer. I need a board which works with the smaller type of flight controller like the CC3D which narrows down the options a bit.

Power distribution boards

As you can see I even managed to two of the same kind. The middle ones are the same but with different colors and different brands.

The leftmost one is the one I actually need. It has the same dimensions as my CC3D board and will fit perfectly in a mini quad. It's rated at 50 amperes, which is probably not true, but even at half of that I still have a margin down to 20 amperes where my mini quads peak. I've only found those boards at HobbyKing so far.

The middle ones are essentially the crius board and a clone. They could have been a good pick. As you can see they have a double set of mounting holes, the outer ones which would fit a larger flight controller like the KK board and a set of inner ones. But the inner ones are too widely spaced for a small flight controller. If I find a board like this but with inner holes which fit the CC3D I will buy and use it.

The rightmost is a bit of an odd piece. It has built-in DC-DC converters (BEC). One rated at 12V and the other one variable 3-20V, which is practical. Sadly the placement of the soldering pads, with one pole at each sides, makes it more of a power board than an actual distribution board. With this board you'll still get cables going back and fourth, but you can loose one or two BECs from your build.


Edit: The middle boards are designed for the MultiWii controller which commonly has 35mm hole spacing whereas the CC3D and Naze32 has 30.5mm spacing.

August 13, 2014

Naze32 from HobbyKing

I have chosen to use the CC3D for my mini-quad builds lately. This is mainly because the Naze 32 has been hard to come by from time to time and that it is a bit unclear whether the board support S-BUS or not.

It seems the first argument just went away. HobbyKing just published their daily and they are now carrying the Naze32 under their name AfroFlight. I'll be ordering it as soon as I get my refunds for the orders I never got!


August 10, 2014

This is CopterX

My CopterX 450 failed miserably during its last flight. The tail servo mount broke in-flight. I had to take it down hard but managed to save everything but the landing gear. Lucky save I would say.

So what happened? Well, see for yourself. The tail servo holder does not seem to made out of the highest quality aluminium, that's for sure.



CopterX servo mount
Broken CopterX tail servo mount.

August 8, 2014

Simple LC-filter for the X900

I haven't been flying the X900 much for a couple of reason. Firstly it does not fly well with the firmware I loaded into the KK board. I haven't taken the time to fix this simply because the FPV system isn't working well either.

The FPV setup has a big issue with both jello and motor/esc interference. The jello problem comes from a prop mount which isn't straight. It came like that in the box but took me a while to discover the problem. Apparently I'm not alone with this issue. If you choose to buy the cheap NTM prop drives with accessories from HobbyKing, buy a few extra to save the 3-4 weeks wait for replacements.

I took care of the interference problem today by building a simple LC filter. I made it simpler than most recommendations and used only a solenoid and an electrolytic capacitor. This is mainly because I had no ceramic capacitors on the shelf. Next time, I'll put one of those into it as well to really really overdo it just in case.

LC filter on the X900. Sorry for the crappy image.

August 7, 2014

Using an accessory on the controller outputs on the CC3D

When using the CC3D board on a quad copter the controller has two left over outputs directly accessible on the board. The left over outputs can easily be used for gimbal output since the software has a built in configuration tool for it. But what if you would like to run any arbitrary device on this outputs.

First of all, you can use the Receiver port for PWM output. If this is an option, go for that instead which would be much easier. But in my case I use S-BUS which leaves the Receiver port empty and for installation purposes I would like to keep it like that, there is after all a PWM output with pins available.

I did figure out a way to use one of the output pins through the manual mixer for any arbitrary input channel. This way can also be used to use the flight mode channel (if you are short in transmitter channels) to mix it into an accessory output.

First I assign my channel to an input under the input tab. This is really simple and has full support in the GCS. Here I just pick S-BUS channel 6 to be assigned to the internal channel Accessory0.




The next step is to setup the mixer. This requires manual mixing and for some reason the GCS is somewhat limited here. But if you have already setup you craft configuration everything should be fine and you can fiddle with only a few values in the manual configuration tool.

I will use the ThrottleCurve2 as input to the mixer. Obviously, you wont be able to use that curve for flying any more. Under the configuration tab go to MixerSettings. Change Curve2Source to Accessory0, our channel 6. Then change Mixer5Type to servo (or whatever) and under Mixer5Vector type 127 into ThrottleCurve2. And thats it!




It seems that after having done this, the GCS GUI won't work for changing the mixer settings and you will have to live will the manual configuration from now on.

August 4, 2014

Diatone 17# v3, with power distribution built in

Having spent quite a few hours on the power distribution on the Diatone 17# v1 I stumpled upon an updated version. The Diatone 17# v3 has built-in power distribution in the bottom clean plate. If this build turns out good, that is what I'm building next!

I also noticed the Diatone 18#, which is essentially a very similar frame but not a clean-dirty design. And v3 has power distribution!

The Diatone frames are closing in on the blackout in terms of features. But do they withstand the same amount of violence?

July 31, 2014

Stuff for the Diatone 17# has started to arrive

I had a few parcels waiting for me at the post office when I got back from the vacation the other day. I have the frame, motors, ESCs, along with some other parts, which is enough for me to start planning and building the dirty part of the multirotor.

I had planned to use a power distribution board for this build as I had limited success in building the power harness in simple and good looking way before. But I got inspired by Bruce's build video of his chinese mini quad and decided to go for the standard wire harness as it fits neatly between the bottom plates.


Parts for the Diatone 17#

July 28, 2014

The Laser230 IS a Diatone 17#

No doubt about it. Just got my Laser230 from HobbyKing and it is not a ripoff of the Diatone 17#. It is a Diatone 17#.


July 23, 2014

Review and build video of chinese mini h-quad by Bruce

Bruce (rcmodelreviews) just published a great review and build video of a chinese noname mini h-quad. In his review he compares them in quality and design with the QAV250 and the Blackout mini h-quad. I can't wait to get my own build started, but the motors from myrcmart have not even been shipped yet.


July 16, 2014

One more millimeter please

I finally got the long frame upgrade for the FPV250. It took Malaysia post no less than 44 days to get it to me and I'm not too happy about that since HobbyKing has launched a third generation in the mini-quad series and I will probably not build anything with this frame. In fact, I have already a ordered the Laser230 / Diatone 17.

Anyway. I had to check it out. Not much too say, it's three pieces of something that looks like thick carbon fiber but feels heavier than expected, a set of metal standoffs and socket button head screws.

I just so happen to have a board camera arrive the same day, a Sony Super HAD-II, which I think is better than the Fatshark cameras I have had before. This frame is supposed to be good for board cameras but no. My particular camera is 1mm too big for the frame. 1mm? I can fix this with a few washers.

Long frame front with Sony board camera.

July 7, 2014

New mini-quad motors announced by myrcmart

Myrcmart has announced their launch of a new generation of motors for mini-quads. This was probably some time back, but I haven't noticed until now when I started looking for a budget motor for my next build.

They now offer a slightly bigger version of the 1804, namely the 1806. I fly the 1804 now and I am very pleased, but a friend of mine has gotten much further in flying skills and think the 1804 is not delivering in sharp turns and avoidance manoeuvres.

In addition to this new motor they also have a smaller 1306, it's too small for a 230-250-size but would be very interesting for a smaller build, say a 200. A sub 200 would probably be great for FPV but wouldn't be able to carry a heavier camera (Mobius) for recording.

New mini-quad frames from HobbyKing

HobbyKing announced today their "third" generation of 250-size quad frames. That is counting the intermediate long frame for the original FPV 250.

The new frames are the low-hung clean-dirty frame addition to the original FPV250. I think this design is stupid as it will brake the expensive stuff on a hard landing. However, it has the advantage of being based on the FPV250 which is itself unbreakable.

The next one is a folding 230-size frame. It looks not very thought-through, as those arms wont fold much when there is a motor, prop and ESC on it. And the result might be a half-foldable quad with arm rigidity sacrificed for nothing.

The last one, my pick, is the non-folding version of the above, called the Laser230. It is obvious that it is inspired (please replace by your favorite expression for this thing) by other mini sized quads. It looks less rigid than the originals, having only one "carbon fiber" layer on the arms. It also lacks power distribution.

Of course, I've ordered one right away, my FPV250 v2 will probably build on this frame.






Update: The FPV250LH, Switchblade 200 and Laser230 seems to go by the names FPV250 v3, Mini 200 v1 and Diatone 17#, respectively.

July 6, 2014

HobbyKing parcels via Malaysia stuck?

It's been 40 days, and counting, since my last order from HobbyKing. And the parcels tracking number is not even registered with my domestic courier yet. I normally receive parcels from HobbyKing, sent with the cheapest shipping option, within 20 days, often around 14. But this time my orders seems to have gotten stuck.

It turns out HobbyKing is blaming Malaysia Post. And they are probably right to do so. HobbyKing says Malaysia Post claims that the backlogs should be cleared by end of June. But I doubt it. Another writer seems to have been experiencing delays already since April. Will Malaysia Post walk the same path as Fiji Post. And will we then get the Hong Kong post service back even with HobbyKing?

Update: My next order was shipped via Singapore. I really hope this doesn't mean that even more delay is to be expected for the three parcels stuck in Malaysia.

June 27, 2014

Prop and slot on the Bixler

I mentioned earlier that I tried to change motor to a slightly higher Kv while keeping the same propeller as before to slightly improve the top speed and static thrust. This while at the same time removing the motor mount upgrade which gave the Bixler some strange flight characteristics. However, despite what I had measured with the greatest of precision the 7x5 prop would not fit with the lower mount.

Well, I had to do something. Why not some cutting? I cut a slot into the tail to give the propeller the clearance it needs. This came with a small surprise, the tail is like a hollow tube.


Bixler propeller slot
Tail slot with propeller

I knew that this cut would impact the already not-so-rigid tail of the Bixler. And it did, most notably. To counter this I added two carbon fiber rods closely to the newly cut slot. This is in addition to the earlier upgrade of the tail with a carbon fiber rod on the bottom. With the three rods in place the tail is now very rigid.

Additional carbon fiber rod
Carbon fiber rod enforcement on the tail

Since I used a pusher prop before, and the 6x4 one I tried was not I had to switch a pair of cables to make the motor turn the right direction. There is no real advantage to having a pusher prop on a plane like this except that you don't have to locktite the nut on the propeller shaft.

June 22, 2014

Badly packed stuff from HobbyKing

I got a package from HobbyKing today! Always feels like Christmas when a package gets delivered. But seriously, get your packers to do their work a little better! It looks like they've just thrown everything in there with. Considering that it contains 6 LiPos this is not fantastic treatment...


HobbyKing packing style

Bixler FPV

I've started my work on an FPV addition to my good old Bixler v1.1. I've flown this plane quite a lot. And crashed it a lot, being my first plane. I still love it and have no intentions on retiring it and therefore it will get some new stuff that might make it fly better and be able to teach me fixed wing FPV.

The main goal is to

  • Add a simple camera and video transmitter to the fuselage
  • Improve the motor configuration to give it some more thrust
  • Split the power distribution into three circuits (ESC,BEC,FPV) but with one battery

FPV


First off is the LC filter. I've had some bad experiences running without a filter and it seems random whether your other electronics will cause interference or not. From now on I will just add the filter from the start and be done with it already. This is the typical LC-filter. A coil and a capacitor from ebay, just like that.

FPV LC-filter to kill off any interference from the ESC or BEC.

This is the Bixler FPV mount from HobbyKing. I've had this in the drawer for over a year now. It comes together better than expected and fits fairly well. I could have done a better job on the angles of the forward support but it'll work just fine.


HobbyKing Bixler FPV mount

The camera, a Sony Super HAD-II off of ebay. Everyone says it's great and that's enough for me. I've only used Fatshark cameras up until now and I'm not impressed with them. This camera is half the price and from the comparisons I've seen it should be twice as good. I'll see for myself in the near future...

Sony Super HAD-II board camera

The camera mounted on the FPV mount. Anyone how knows more than what I knew at the moment will notice that it is mounted upside down. I learned that much later. But no I know too.


FPV mount with board camera

Everything in place on the FPV mount. The camera is still upside down on this picture, guess I haven't realized my mistake yet. I also did another mistake while putting together the power cables for the video transmitter. I mistakenly connected power and ground on the output side of the video transmitter. This particular transmitter has a 5V output on this connector. If i hadn't realized this right before connecting the setup the the battery I would probably have had a pile of carbon on the next picture.


FPV mount with filter, transmitter, camera and antenna


FPV mount on the Bixler. Without the rubber bands to hold it in place.


Motor upgrade

The previous setup was a 950Kv motor and a 7x5 prop mounted on an extension to place it higher up to allow for a bigger propeller. This setup was very power efficient and silent but I had much less static thrust and a low top speed. The top speed is not really an issue but I would like to more thrust for easier take-offs. The mount also had some weird effects on flight characteristics. The plane tenden to tip forward on low speed but acted as if it was tail heavy in cruising speed.

I removed the extended mounting with hopes of having enough free space to be able to keep the same prop but with a faster 1250kv motor. This was not the case and I've now put on a 6x4 prop instead. It does not give me the thrust I would like during "bench testing" and I will probably need to work some more on this solution.


Power system


I wired up a new power system including an e-fuel gauge and cabling for the ESC, BEC and a JST connector for the FPV mount. I had some issues with heat from the ESC before but I suspect that it is mostly from the built-in linear BEC. Using an external switched-mode BEC should solve this problem.

Bixler power system






June 3, 2014

KK Flight controller from dx

I just received a KK 5.5 flight controller board from dx.com. I didn't order this board, in fact I ordered an USBAsp but the item was mislabeled in the warehouse and I got a controller board instead.

I wouldn't have ordered this in the first place since I've gotten used to flying the CC3D which is much better. And after having seen this board I'm even more skeptic to these cheap boards.

As you can see from the pictures the board is dirty. Very dirty. It's as if it has already been used, gotten wet and left to dry without cleaning. The soldering looks alright, with the exception of a few components which are not mounted straight.

Now what to do with this device? Maybe I should try it in my upcoming Bixler FPV build to get flight stabilization...

KK 5.5 Board, top side

KK 5.5 Board, bottom side